Structural stiffness calculation method for aircraft folded wing

In order to improve the efficiency and accuracy of the calculation of the structural stiffness of the aircraft folded wing, this manuscript proposes a semi-analytical calculation method of the structural stiffness considering the thickness of the variable cross-section. To handle the characteristics of the folded wing structure of the aircraft, a stiffness analysis model is established, and the numerical solution of the deflection of the dynamic airfoil segment is obtained by introducing the expression of the bending stiffness of the member as a function of the shape of the cross-section and by using the Rayleigh-Ritz method. In order to further improve the accuracy of the stiffness calculation, a mechanical model of the locking mechanism is introduced to give the deflection and angle of the boundary of the folded segment. The total deflection of the folded wing under the given working condition is obtained by the superposition principle, by which the structural stiffness is obtained. A case study is conducted on a typical folded wing structure, and the results show that the proposed method can significantly improve the computational efficiency, where at the same time the accuracy of the stiffness calculation is ensured, which can be used to support the fast iterative design of aircraft folded wings in a limited way.